Vehicle interiors typically are constructed with a variety of panels that provide aesthetic appeal while also providing some form of energy absorption during an impact event. Such panels include the knee bolster panel attached to the cross-car beam energy absorbing bracket. Other such panels are attached to the vehicle door and to the console.
There are several challenges facing the designers of vehicle interiors. One of these challenges is vehicle safety regulations related to the protection of unbelted front seat occupants. In conjunction with the steering wheel and air bags, the instrument panel itself plays an important role in managing the energy exerted by the occupant during impact. Particularly, energy exerted by the occupant's knees during such impact is an aspect that must be effectively and safely dissipated through proper management. The instrument panel cross-car beam, its associated substrate, and the knee bolster cover together consist of a knee impact energy management system. A knee load target is cascaded to this system, requiring a specific knee load rate, maximum peak and proper knee travel distance. Each component of the system has its essential role and works together to accomplish the stated goals.
Accordingly, a design challenge for interior designers is to properly connect the panel to the bracket of the underlying structure. Adding to this challenge is the fact that while the panels may vary from model to model to support styling needs, very often the underlying brackets and related structure remains relatively unchanged between models, thus the designer must adapt different panels to attach to the same brackets.
Previous solutions required the re-designing and re-tooling of the cross-car beam energy absorbing brackets and related components to bridge the spatial gap between the knee bolster panel and the brackets. Some manufacturers have used foam blocks for this purpose. While providing certain clear advantages, the blocks present at least three difficulties. First, foam blocks are not necessarily the best structure to transfer energy. Second, during assembly foam blocks sometimes are improperly aligned or are inadvertently left out by the assembler. Third, the use of foam blocks adds additional material and assembly cost.
Accordingly the interior designer needs to find a practical, safe and cost-effective solution to the need to adapt different panels to the same instrument panel structure by bridging the spatial gap between the inner side of the panel and the supporting bracket to which it is attached.